A mechanical and electric drive train of a hybrid vehicle is known from DE 10 2011 053 832 A1. In this drive train, an internal combustion engine and an electric motor are coupled to the drive wheels. The internal combustion engine and the electric motor are connected to a common input shaft of the gearbox wherein the gearbox transmits the power of one or both motors to an axle of the vehicle.
The disadvantage of the known drive train is that, firstly, an electric motor and an internal combustion engine must be arranged on one side of the gearbox, so that typically, there must be space for both motors in one engine compartment. A further disadvantage is that both motors are connected via the gearbox to the drive shafts of the driven axle so that this drive train is barely able to be configured for purely electric motor operation, since in this case, the gearbox is not necessary. The electric motor would thus have to drive the gearbox which would lead to unnecessary losses. For this reason, the known drive train is provided only for supportive electric motors wherein the motor vehicle is substantially driven by the internal combustion engine.
A further mechanical and electric drive train of a hybrid vehicle of this type is known from DE 10 2007 037 758 A1. In this drive train, the internal combustion engine and the electric motor are also arranged before the gearbox, so that this drive train also has the same disadvantage as that described above.
The drive train of a motor vehicle typically consists of the components which transmit the force of the drive motor or, if a plurality are present, of the drive motors, to the drive shafts of the driven axle or axles. In the first place, in the case of an internal combustion engine-powered motor vehicle, this is the shift gearbox which is connected to the engine via an automatic or mechanical clutch by which the driver can select various transmission ratios (gears).
It is also usual, but not essential, that a power transmission unit (PTU), by which the drive force is transmitted from the output shaft of the gearbox either directly to a differential or to a propeller shaft is arranged behind the shift gearbox. If the power transmission unit acts directly on the differential, both gearbox units can also be arranged in one common housing.
In the case of power transmission by means of a propeller shaft, a further gearbox (drive unit) is typically arranged at the end of this propeller shaft as an axle drive unit, by which the drive force is distributed to the drive shafts of the driven axle.